Enantiomerically pure zirconium and hafnium complexes containing a chiral cyclopentadiene derivative prepared from (-)-β-pinene

Article abstract of DOI:10.1016/S0957-4166(97)00588-0

Chirally homogeneous (1S,8R)-3,5,9,9-tetramethyltricyclo[6.1.1.0^2,6] deca-2,5-diene 1 has been prepared in five steps and 42% overall yield from (-)-β-pinene; its successive treatment first with n-BuLi and then with ZrCl₄ or HfCl₄ provides, in high yields with high π-facial selectivity, the corresponding dichlorobis{η⁵-(1S,8R)-3,5,9,9-tetramethyltricyclo [6.1.1.0^2,6]deca-3,5-dien-2-yl}zirconium or hafnium, respectively.